Back in the early days of the reality-TV wave, a prevailing notion about the genre was that people on such shows were using them as springboards to other showbiz careers. That hasn't really come to pass. Just ask, well, about 90 percent of the participants on every reality show of the past seven or eight years. There's at least one exception to that rule, though: The celebrities who appear on "Dancing with the Stars" have a pretty good record of using the show to advance their careers. (We're not saying they suddenly become A-list icons, but every little bit helps, you know?) Maybe it's because we already know them anyway, or that they aren't subjecting themselves to anything more embarrassing than a subpar tango or quick-step. The show's giant ratings probably don't hurt either. But a number of past "Dancing" contestants have gotten noticeable career boosts. With contestants for the next season set to be announced Monday, Aug. 30, who will be the next beneficiary of the "DWTS" boost?